[patch 37/38] x86: Select ARCH_HAS_RANDOM_ENTROPY

Thomas Gleixner
2026-04-10T12:21:49Z

The only remaining usage of get_cycles() is to provide random_get_entropy().

Switch x86 over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY and
providing random_get_entropy() in asm/random.h.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: x86@kernel.org
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/random.h | 16 ++++++++++++++++
arch/x86/include/asm/timex.h | 17 -----------------
arch/x86/include/asm/tsc.h | 9 ---------
4 files changed, 17 insertions(+), 26 deletions(-)

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -101,6 +101,7 @@ config X86
select ARCH_HAS_PREEMPT_LAZY
select ARCH_HAS_PTDUMP
select ARCH_HAS_PTE_SPECIAL
+ select ARCH_HAS_RANDOM_ENTROPY
select ARCH_HAS_HW_PTE_YOUNG
select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
--- /dev/null
+++ b/arch/x86/include/asm/random.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_RANDOM_H
+#define _ASM_X86_RANDOM_H
+
+#include <asm/processor.h>
+#include <asm/tsc.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+ if (!IS_ENABLED(CONFIG_X86_TSC) &&
+ !cpu_feature_enabled(X86_FEATURE_TSC))
+ return random_get_entropy_fallback();
+ return rdtsc();
+}
+
+#endif /* _ASM_X86_RANDOM_H */
--- a/arch/x86/include/asm/timex.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_X86_TIMEX_H
-#define _ASM_X86_TIMEX_H
-
-#include <asm/processor.h>
-#include <asm/tsc.h>
-
-static inline unsigned long random_get_entropy(void)
-{
- if (!IS_ENABLED(CONFIG_X86_TSC) &&
- !cpu_feature_enabled(X86_FEATURE_TSC))
- return random_get_entropy_fallback();
- return rdtsc();
-}
-#define random_get_entropy random_get_entropy
-
-#endif /* _ASM_X86_TIMEX_H */
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -72,15 +72,6 @@ extern unsigned int tsc_khz;

extern void disable_TSC(void);

-static inline cycles_t get_cycles(void)
-{
- if (!IS_ENABLED(CONFIG_X86_TSC) &&
- !cpu_feature_enabled(X86_FEATURE_TSC))
- return 0;
- return rdtsc();
-}
-#define get_cycles get_cycles
-
extern void tsc_early_init(void);
extern void tsc_init(void);
extern void mark_tsc_unstable(char *reason);